zerodrop-mcp

Email verification for AI agents — an MCP server that gives Claude, Cursor, Claude Code, and any MCP client disposable email inboxes with auto-extracted OTPs and magic links.

Your agent signs up for a service. The service sends a verification code. Without an inbox it can read, the agent is stuck. With zerodrop-mcp:

Code

Agent: generate_inbox()
  → swift-x7k29ab@zerodrop-sandbox.online

Agent: [fills the signup form with that address]

Agent: wait_for_email(inbox, require_otp: true)
  → { "otp": "847291", "subject": "Verify your email", ... }

Agent: [enters 847291 — flow complete]

No Docker. No SMTP. No API key. No signup. Free tier works out of the box.

Install

Claude Code

Terminal

claude mcp add zerodrop -- npx -y zerodrop-mcp

Claude Desktop

Add to claude_desktop_config.json:

config.json

{
  "mcpServers": {
    "zerodrop": {
      "command": "npx",
      "args": ["-y", "zerodrop-mcp"]
    }
  }
}

Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

config.json

{
  "mcpServers": {
    "zerodrop": {
      "command": "npx",
      "args": ["-y", "zerodrop-mcp"]
    }
  }
}

Tools

`generate_inbox`

Creates a disposable email address. Local and instant — no network request.

Param	Type	Description
`prefix`	string, optional	Prefix for the inbox name, e.g. your app name

Returns the inbox address and a live watch URL.

`wait_for_email`

Blocks until a matching email arrives, then returns it with the OTP and magic link already extracted — the agent never parses HTML or regexes a body.

Param	Type	Description
`inbox`	string	Address from `generate_inbox`
`timeout_seconds`	number, optional	Default 30, max 120
`from_contains`	string, optional	Filter by sender
`subject_contains`	string, optional	Filter by subject
`require_otp`	boolean, optional	Only match emails with an OTP
`require_magic_link`	boolean, optional	Only match emails with a magic link

Returns:

config.json

{
  "from": "noreply@yourapp.com",
  "subject": "Your verification code",
  "received_at": "2026-07-18T12:34:56Z",
  "otp": "847291",
  "magic_link": null,
  "body_preview": "Your code is: 847291..."
}

`check_inbox`

Non-blocking snapshot of the inbox — recent emails with extracted fields, or an empty list.

What agents use this for

Testing auth flows end to end — signup → OTP → verified, driven entirely by the agent
QA automation — Claude Code writing and running Playwright tests that need real inboxes
Autonomous workflows — any agent task that hits an email-verification wall
Development — "sign up for my own app and tell me if the verification email works"

How it works

Emails sent to a generated inbox are caught at Cloudflare's edge by ZeroDrop's open-source worker. OTPs and magic links are extracted at the edge before your agent reads them. Inboxes auto-delete after 30 minutes on the free tier.

Configuration

Environment variables (set in your MCP client config):

Variable	Default	Description
`ZERODROP_API_KEY`	—	Workspace key. Omit for free sandbox mode.
`ZERODROP_BASE_URL`	`https://zerodrop.dev`	Self-hosted instance URL

config.json

{
  "mcpServers": {
    "zerodrop": {
      "command": "npx",
      "args": ["-y", "zerodrop-mcp"],
      "env": { "ZERODROP_API_KEY": "your-key" }
    }
  }
}

Writing tests instead?

If you're generating test code rather than driving flows live, use the SDKs directly:

npm · PyPI · Go · RubyGems · Packagist · JitPack · GitHub Action

AI coding assistant context: docs.zerodrop.dev/ai-coding

Security

The server makes requests only to ZERODROP_BASE_URL (zerodrop.dev by default) — nothing else
Inbox generation is fully local
Two runtime dependencies: the official MCP SDK and zod
Report issues: founder@zerodrop.dev

License

MIT — zerodrop.dev